Lycan’s Four Objections to Substance Dualism
This is from Lycan’s contributions to the Blackwell Companion to Philosophy (“Philosophy of Mind”):
1. Immaterial minds do not fit with the emerging picture of the physical world. Science keeps peering further into the nature of previously mysterious areas and gives us a causal account of things explicable in terms of physical goings-on.
I have to admit that, although we are left without a specific objection here, this one probably makes the dualist quiver the most. It was a combination of this kind of objection coupled with the arguments for the non-identity of mental states to brain-states that drove me into the arms of Emergent Dualism. However, this objection ought not to level anyone’s belief about the mind as long as they have significant reasons for rejecting reductionistic accounts.
2. Evolution would’ve had to produce immaterial minds somewhere along the lines of our lineage which seems improbable/inexplicable. How and when would this have happened?
Actually, I would extend this objection to non-dualists as well- why in the world did nature suddenly produce and select consciousness? Isn’t that something just as mysterious? Unless naturalists can provide a reason for the existence of consciousness, they are left gasping for explanation. Further, most dualists are not just dualists about philosophy of mind but of explanations as well. To elaborate a bit, we explain phenomena not just in terms of physical laws (of selection, genetics and neurobiology, for instance) but of teleology. Nature and her laws are here to produce some kind of effect; namely, consciousness. Therefore, we will not exhaust an explanation of the mind by recourse to physical history of biological entities (even though such a history is important).
3. How can minds interact in space-time if they are immaterial?
One can then ask, how does matter interact with other matter? What is causation, and what exactly allows the causal relation between physical entities? The point being, there is no formal contradiction in saying that immaterial minds and material bodies interact with each other. It may be mysterious, but no more mysterious than the nature of causation or physical relations.
4. There must be some kind of exchange of energy if the mind is to interact with the body (laws of conservation and so on).
To be honest, I don’t get this objection. We do not understand the mind very much at all yet, so it is difficult to speak with any kind of force to this issue. There are possible answers to this questions, however. There could be some kind of psychic energy (which I think has been put forward by John Eccles), or perhaps “holes” in the laws of conservation via Quantum Mechanics, or maybe we do not live in a closed system and so the mind would introduce new “energy” into our system without violating said laws. Further, our thinking on the matter may be entirely egregious at the moment considering our vastly small understanding of the physical world. In other words, I take a wait-and-see approach with this last objection.